Railway-signal.



J. S. HOBSON.

RAILWAY SIGNAL.

APPLICATION rum) P114, 1908,

2 SHEETS-SHEET 1.

Patented July 6, 1909.

l Vihwaau attain,

s. nossou. RAILWAY SIGNAL.

APPLICATION FILED SEPT. 14, 1908.

Patented 'July 6, 1909.

2 SHEETS-SHEET 2.

Annual, a. mum co. mow-uwwwns. msmmnm n a UNITED srATnsrarnNr OFFICE.

JOHN S. HOBSON, OF EDGEWOOD PARK, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYL VANIA.

RAILWAY-SIGNAL.

Specification of Letters Patent.

Application filed September 14, 1908.

Patented July 6, 1909.

Serial No. 462,806.

To all whom it may concern:

Be it known that I, JOHN S. HoBsoN, a citizen of the United States, residing at Edgewood Park, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Railway- Signal of which the following is a specification.

This invention relates to air buffers for railway signals and particularly to the semaphore type of railway signals each blade of which is used to give a plurality of indica' tions, and irrespective if it is moved upwardly or downwardly on its pivot.

I will describe preferred embodiments of my invention and then point out the novel features in claims.

In the accompanying drawings in which like reference characters designate similar parts in the respective figures, Figure 1 is a sectional view of one form of my improved air buffer. Fig. 2 is a similar view of the same form in a different position. Figs. 3, 4 and 5 are views, partly in section and partly in elevation, showing a semaphore signal in three different positions and my preferred form of air buii er in the three different corresponding positions. In these figures certain details of construction are omitted. Fig. 6 is a sectional view of a modified form of my invention. Fig. 7 is a view similar to Fig. 6 but showing the parts in a different position.

The semaphore blade is designated by 10 and the spectacle casting by 11. If the blade is moved from its horizontal position down wardly on its pivot to its inclined and vertical positions, the spectacle is made sufficiently heavy to always tend to move the blade to its horizontal position. If on the other hand the blade is moved from its horizontal position upwardly on its pivot to its inclined and vertical positions, the weight of the blade and spectacle casting are both employed to return the blade to the horizontal position. Both of these arrangements are well understood in the art, and my invention is applicable to either. The spectacle casting and blade are suitably fastened together and they are provided with a shaft 12 which is suitably ournaled, and arm 13 is provided, generally on the shaft 12, to which is connected the up and down rod 15 through which the blade is moved from its horizontal to its inclined and vertical positions.

The up and down rod 15 may derive one of its longitudinal movements from any desired type of motor. Its reverse longitudinal movement may in some cases be obtained by its own weight and that of the parts connected to it when the rod is released from the position to which it has been moved, or its reverse movement may be obtained through the motor, in which casein automatic signals its upward movement is under the influence of the counterweight of the signal. In the drawings I have shown the rod 15 connected with What is known in the art as a slot arm 16, which as usual is pivoted at one end, and provided with levers and electro-magnets by means of which its pivoted lever 16 may be held rigid and engage projections on a chain driven by a motor and thereby move the rod 15 upward. An illustration of this arrangement of parts is disclosed in United States Patent No. 611,943 granted October 4, 1898, upon an invention of J. G. Schreuder. The downward movement of the rod 15 is cushioned to prevent shock and a butter is employed for this purpose. My invention relates particularly to the buffer, which is an air buiier and preferred forms thereof will now be described.

Figs. 1 to 5 illustrate one form which, as will be seen, comprises two cylinders telescopically arranged, while in Figs. 6 and 7 the two cylinders are arranged side by side. The principle of operation of the two forms, however, is the same. That is, one cylinder acts as a buffer in the movement of the rod 15 and. with it the blade from one position of indication to another while the other cylinder acts as a buffer in the movement of the blade from that position to still another position.

Referring now particularly to Figs. 1 and 2, 19 designates a frame adapted to be pivotally connected at 20 to any suitable support, not shown. 21 is a piston, the rod 22 of which is secured to the support 19. A cylinder 23 is fitted over the piston to slide thereon, the latter being provided with suitable packing 24. The cylinder 23 in turn serves as a piston for another cylinder 25 which slides thereon and is connected at its upper end to a rod 18 which is also suitably connected with the slot arm 16. The upward movement of the cylinder 25 on the cylinder 23 is limited, and this may be accomplished through opposite grooves 26 in the wall of the cylinder 23 into which pins or set screws 27, secured to the cylinder 25, project. The pins 27 engaging the upper ends of the grooves 26 serve to raise the cylinder 23 upon the iston 21. The upward movement of the cy inder 23 on the piston 21 is limited by means of a pin 29 carried by the cylinder 23 and extend mg through a slot or opening 28 in the stem 22.

The two cylinders occupy the position shown in Figs. 1 and 3 when the blade is in a horizontal position and which indicates danger or stop to a driver of a motor car i or train traveling along the railway. When the signal motor is operated to move the blade from its horizontal position, the up and down rod 15 will carry with it the rod 18 and cylinder 25 upwardly, and by the time the blade has reached its intermediate inclined or caution position, the pins 27 will have reached the upper ends of the grooves 26, as shown in Figs. 2 and 4. If the next movement of the blade is back to its horizontal or danger position, the descent of the cylinder 25 will compress the air and thereby form a buffer to relieve the parts from shock. If, however, the blade is moved from its inclined position to its vertical or safety position, then the further upward movement of the rod 15 will carry the rod 18 and cylinder 25 higher and the pins 27 by their engagement with the upper ends of the grooves 26 will cause the inner cylinder 23 to move up on the piston 21 to the position shown in Fig. 5 when the pin 29 will engage the upper end of the slot 28.

On the return movement of the blade it is necessary to hold the inner cylinder 23 against downward movement until the outer cylinder 25 has moved down to its full ex tent over the cylinder 23, and to do this I preferably provide hooks 30 pivoted at their upper ends in the frame 19. Springs 31 tend normally to press the projections 30 of the hooks inwardly toward the cylinders, and when the inner cylinder 23 has reached its hi hest point the projections 30 will be force under its lower edge and thereby hold it against downward movement. When the outer cylinder 25 has nearly completed its downward movement on the cylinder 23 it will engage the projections 30 on the hooks and force the latter out of engagement with the edge of the cylinder 23 and the latter will then be free to move downwardly. The projections 30 may if desired be in the form of rollers.

It will be understood, of course, that the blade and the up and down rod are suitably I supported against downward by sultable devices comprised in the signal movement operating mechanism except, of course, at such times as desired that the blade shall give different indications, and that the buffer mechanism embodying my invention is for the purpose of cushioning the downward movement of the up and down rod 15 and parts connected therewith.

It is, of course, necessary to provide valves which will open freely for the admission of air during the upward movement of the cylinders, and also to provide valves which will permit the air to escape slowly during the downward movement of the cylinders. These valves may be of any suitable or well known construction. As shown I form a pocket 32 in the piston 21 which communicates freely with the outer air and is provided with a seat for a ball valve 33. A similar pocket 34 is provided in the head. of the inner cylinder 23 and, has a seat for a ball valve 35. These valves will open freely to admit air when the cylinders are moved upwardly but will close under the pressure of air within the cylinders when the latter move downwardly. Strips of metal 36 project over the pockets to prevent the balls being forced out of them.

In Figs. 6 and 7 the cylinders are arranged side by side. Here the frame 19 has two pistons 41 and 42 secured to it upon which two cylinders 43 and 44 work up and down. A plate or bar 45 extends up between the two cylinders and is rigid with the frame. A pin 46 is loosely supported in the bar 45 and has conical ends adapted to enter conical recesses 47 and 48 in the cylinders 43 and 44 respectively. The upper ends of the two cylinders are connected by a floating lever 49 to the middle of which the rod 18is connected.

Normally, when the blade is in its horizontal position, the cylinder 43 will be down level with the cylinder 44, one end of the pin 46 will be in the recess 48 and the other end will be either engaged by the surface of the cylinder 43 or in close proximity to it, the recess 47 being then some distance below the pin (see Fig. 7). As shown in Fig. 6 the blade is supposed to have moved the cylinder 43 up to its limit. Further movement of the blade to its vertical position will lift the cylinder 44 and such movement will force the pin 46 into the recess 47 and when the cylinder 44 has moved up to its limit the blade will be in its vertical position and the floating lever will be substantially horizontal. The cylinder 43 will be locked against downward movement by the pin 46, so that when the signal begins its return movement the cylinder 44 will first descend until its recess 48 is opposite the pin 46 when the cylinder 43 can be moved downwardly.

It will of course be understood that the cylinders 43 and 44 will be provided with valves for the free admission of air and its slow discharge, but I have not deemed it necessary to illustrate them, as substantially the same valve arrangement as shown in Figs. 1 and 2 might be employed, or any other preferred arrangement.

Many details of construction are omitted in Figs. 3, 4 andv 5, as they are intended to illustrate different positions of the principal parts only.

In either form of my invention. two cylinders are employed to act as buffers with but a connection to the signal and in each case means are provided for locking one cylinder against downward movement until the other has finished its downward movement when the latter releases the locking means.

Having described my invention, I claim:

1. The combination with a signal blade, of an air buffer comprising two pistons and two cylinders, a connection between the two cylinders and the signal blade, and means for causing the two cylinders to move successively.

2. The combination with a signal blade, of an air buffer comprising two pistons and two cylinders, a connection between the two cylinders and the signal blade, and means for locking one cylinder against downward movement until the other cylinder has completed its downward movement, said locking means being released by the last named cylinder on the completion of its downward stroke.

3. The combination with a signal blade, of an air buffer comprising two cylinders arranged telescopically, a fixed piston to cooperate with the inner cylinder, a connection between the outer cylinder and the signal blade, and means for transmitting movement from the outer cylinder to the innerone.

4. In combination with a signal blade, of an air buffer comprising two cylinders arranged telescopically, a fixed piston to cooperate with the inner cylinder, a connection between the outer cylinder and. the signal blade, means for transmitting movement from the outer cylinder to the inner 1 one on its upward movement, and means for holding the inner cylinder against downward movement until the outward one has completed its downward movement relatively to the inner one.

5. The combination w1th a signal blade, of a frame, a piston. rigid with the frame, a cylinder fitted on the piston, a second or outer cylinder fitted over the first named or inner cylinder, a connection between the outer cylinder and the signal blade, means for limiting the movement of the outer cylinder on the inner one, and means for limiting the movement of the inner cylinder on the piston.

6. The combination with signal blade, of a frame, a piston rigid with the frame, an

innercylinder fitted on the piston, an outer cylinder fitted over the inner one, a connection. between the outer cylinder and the signal blade, a slot and pin connection between the two cylinders, a spring pressed hook supported on. the frame for engaging the lower end of the inner cylinder when the latter has completed its upward movement, and means whereby the said hook is released by the outer cylinder when the latter has completed its downward movement with respect to the inner cylinder.

7. The combination with a signal blade, of a frame, a piston connected with the frame, a cylinder movable on the piston, means for limiting the movement of the cylinder on the piston, a second cylinder movable on the first mentioned cylinder, means for limiting the movement of the second cylinder on the first, a connection between the second cylinder and the signal blade, and valves for permitting the slow escape of air between. the two cylinders and the first cylinder and piston.

8. The combination with a signal blade, a frame, a piston connected with the frame and having a slot in its stem, a cylinder movable on the piston, a pin carried by the cylinder and passing through said slot, a second cylinder movable to the first cylinder, a connection between the second cylinder and the signal blade, means for limiting the movement of the second cylinder on the first and for causing the first cylinder to move with the second, and means for permitting a slow escape of air from between the two cylinders and the first cylinder and the piston.

9. The combination with a signal blade, a frame, a piston connected with the frame, a cylinder having a limited movement on said piston and having recesses provided in its wall, a second cylinder movable on the first, pins carried by said second cylinder and projecting into the recesses in the wall of the first cylinder, a connection between the second cylinder and the signal blade, and means for permitting a slow escape of air from between the two cylinders and the first cylinder and the piston.

10. The combination with a signal blade, of an air buffer for cushioning its movements, said air buffer comprising two telescoping cylinders and a )lShOIl, a connection between the signal blade and one cylinder, a connection between the two cylinders for permitting relative movement between the two, a connection between the piston and a fixed part, and valves for permitting a slow escape of air from between the two cylinders and one cylinder and the iston.

11. The combination with a signal blade, of a frame, a piston connected with the frame, a cylinder having a limited movement on the piston in opposite directions, a second cylinder having a limited movement Ill) on the first cylinder in opposite directions, a In testimony whereof I have signed my connectlon between the second cyllncler and name to thls specl'fication 1n the presence of 10 the slgn al blade and means for engaging and two subscribed wltnesses.

holding one of the cylinders in its extreme position when moved in one direction, said JOHN HOBSON means being operated to release the cylinder Witnesses: upon a reverse movement of the other cyl- C. C. WVHITE,

inder. GEO. H. PFRIL. 

